Liquid transfer device and air conditioner

ABSTRACT

A nozzle electrode ( 44 ) is connected to a drain pan ( 30 ), with the other end of the nozzle electrode ( 44 ) pointing upward and open. A ring electrode ( 45 ) is positioned so as to face the nozzle electrode ( 44 ). When a positive voltage is applied to the nozzle electrode ( 44 ), an electric field is created at a location close to the tip of the nozzle electrode ( 44 ). As a result, a drain water is sprayed from the nozzle electrode ( 44 ) as positively-charged small droplets. The sprayed droplets are discharged to the outside of the system through a flow-in pipe ( 51 ) and a flow-out pipe ( 53 ).

TECHNICAL FIELD

The present invention relates to a liquid transfer device fortransferring a liquid in a reservoir, and an air conditioner includingthe liquid transfer device.

BACKGROUND ART

Liquid transfer devices for transferring a liquid have conventionallybeen used in various fields. As a liquid transfer device of this type,Patent Document 1 discloses a drain pump for discharging a drain waterof a room air conditioner.

The air conditioner of Patent Document 1 includes a so-calledceiling-mounted indoor unit. An indoor heat exchanger through which airpasses, a drain pan (a reservoir) provided under the indoor heatexchanger, and a drain pump (a liquid transfer device) provided in thedrain pan are accommodated in the casing of the indoor unit.

Room air is drawn into the casing and passes through the indoor heatexchanger during the cooling operation of the air conditioner. In theindoor heat exchanger, a refrigerant which flows in the indoor heatexchanger absorbs heat from the air and evaporates, thereby cooling theair. The cooled air is supplied to the indoor space through a pluralityof air outlets. Here, when the air is cooled by the indoor heatexchanger, moisture in the air is condensed and results in a condensedwater. The condensed water falls in drops and is collected in the drainpan. The condensed water stored in the drain pan is transferred upwardlyby the drain pump, and is discharged to the outside of the casingthrough a predetermined pipe.

-   Patent Document 1: Japanese Laid-Open Patent Application Publication    No. 2005-140452

Disclosure of Invention Problems to be Solved by the Invention

In general, the drain pump disclosed in Patent Document 1 is actuated bya motor, and therefore, the operational sound tends to be relativelylarge. Thus, the operational sound of the drain pump may be a noise forpeople in the room. In addition, the drain pump consumes a relativelylarge amount of power due to the motor actuation, which is undesirablein terms of energy saving.

The present invention was made in view of the above, and is advantageousin providing a liquid transfer device with small operational sound andlow power consumption, and an air conditioner including the liquidtransfer device.

Means for Solving the Problems

The first aspect of the present invention is a liquid transfer devicefor transferring a liquid in a reservoir (30). The liquid transferdevice includes a tubular first electrode (44) whose one endcommunicates with the reservoir (30) and whose other end is open, asecond electrode (45) provided at a location corresponding to the otherend of the first electrode (44), and a power source (60) for applying anpotential difference between the first electrode (44) and the secondelectrode (45), thereby creating an electric field at a location closeto the other end of the first electrode (44), wherein the liquid in thereservoir (30) is sprayed from the other end of the first electrode (44)due to the electric field, and thereby the liquid is transferred.

According to the first aspect of the present invention, the reservoir(30) for storing a liquid and the first electrode (44) communicate witheach other. In other words, the liquid in the reservoir (30) can besupplied to the inside of the first electrode (44). When a potentialdifference is applied between the first electrode (44) and the secondelectrode (45) from the power source (60), an electric field is createdat a location close to the other end (i.e., open end) of the firstelectrode (44). As a result, the liquid in the open end of the firstelectrode (44) is polarized, and part of the liquid is pulled apart fromthe air-liquid interface as small droplets. The droplets of the liquidare attracted to the second electrode (45) due to Coulomb force, and aresprayed while keeping the form of small droplets. As a result, thedroplets of the liquid are transferred in a predetermined directionwhile suspended in air.

The second aspect of the present invention is that in the liquidtransfer device of the first aspect, a positive voltage or a negativevoltage is applied to the first electrode (44) from the power source(60), and the second electrode (45) is electrically grounded.

According to the second aspect of the present invention, a positivevoltage or a negative voltage is applied to the first electrode (44)from the power source (60). As a result, positively- ornegatively-charged small droplets are transferred from the open end ofthe first electrode (44) by being attracted to the second electrode (45)which is grounded.

The third aspect of the present invention is that the liquid transferdevice of the second aspect includes a flow-in side guide member (51)for guiding the liquid sprayed from the first electrode (44).

According to the third aspect of the present invention, the liquidsprayed from the first electrode (44) is transferred in a predetermineddirection such that the liquid moves along a flow-in side guide member(51) while suspended in air. Thus, the flow-in side guide member (51)can prevent the sprayed liquid from dispersing, and allows the liquid tobe reliably transferred in a predetermined direction.

The fourth aspect of the present invention is that in the liquidtransfer device of the third aspect, a voltage having a same electricpotential as the voltage applied to the first electrode (44) is appliedto the flow-in side guide member (51).

According to the fourth aspect of the present invention, a voltagehaving a same electric potential as the voltage applied to the firstelectrode (44) is applied to the flow-in side guide member (51).Specifically, if a positive voltage is applied to the first electrode(44), a positive voltage is applied to the flow-in side guide member(51), as well. In this case, when a positively-charged liquid is sprayedfrom the first electrode (44), the liquid is affected by Coulomb forcein a direction separating from the wall surface of the flow-in sideguide member (51). Thus, the liquid is guided to the flow-in side guidemember (51) and transferred while keeping the form of small dropletswithout adhering to the wall of the flow-in side guide member (51).

The fifth aspect of the present invention is that the liquid transferdevice of the third aspect or the fourth aspect includes a flow-out sideguide member (53) which forms a flow path for guiding the liquid thatflows out of the flow-in side guide member (51) and which iselectrically grounded.

According to the fifth aspect of the present invention, the liquid whichflows out of the flow-in side guide member (51) is further guided to theflow-out side guide member (53). Here, the flow-out side guide member(53) is grounded while a positive voltage or a negative voltage isapplied to the first electrode (44). Thus, if a positively-chargedliquid is sprayed from the first electrode (44) and this liquid flowsinto the flow path of the flow-out side guide member (53), the liquid isattracted to the inside wall surface of the flow-out side guide member(53) due to Coulomb force. After the small droplets successively adhereto the inside wall surface of the flow-out side guide member (53), thesedroplets aggregate. Thus, the liquid which has aggregated can flow downin a predetermined direction due to its own weight.

The sixth aspect of the present invention is that the liquid transferdevice of the second aspect includes: a flow-in pipe (51) through whichthe liquid sprayed from the first electrode (44) flows and to which avoltage having a same electric potential as the voltage applied to thefirst electrode (44) is applied; a flow-out pipe (53) through which theliquid that flow out of the flow-in pipe (51) flows and which iselectrically grounded; and an insulating discharge side connecting pipe(52) for connecting between the flow-in pipe (51) and the flow-out pipe(53).

According to the sixth aspect of the present invention, the liquidsprayed from the first electrode (44) flows through the flow-in pipe(51). Since a voltage having the same electric potential as the voltageapplied to the first electrode (44) is applied to the flow-in pipe (51),positively- or negatively-charged small droplets can be prevented fromadhering to the inside wall of the flow-in pipe (51). The liquid whichflows out of the flow-in pipe (51) as described in the above flowsthrough the discharge side connecting pipe (52) into the flow-out pipe(53). The flow-out pipe (53) is grounded, and thus, the positively- ornegatively-charged small droplets are attracted to the inside wall ofthe flow-out pipe (53) due to Coulomb force. As a result, the smalldroplets successively adhere to the inside wall of the flow-out pipe(53) and aggregate. Here, in the present invention, the flow-in pipe(51) and the flow-out pipe (53) are connected to each other by theinsulating discharge side connecting pipe (52). Thus, even when apositive voltage or a negative voltage is applied to the flow-in pipe(51), the discharge side connecting pipe (52) can prevent a current fromflowing from the flow-in pipe (51) to the flow-out pipe (53).

The seventh aspect of the present invention is that any one of theliquid transfer devices of the first to sixth aspects includes aninsulating reservoir side connecting pipe (43) for connecting betweenthe reservoir (30) and the first electrode (44).

According to the seventh aspect of the present invention, the reservoir(30) and the first electrode (44) are connected to each other throughthe insulating reservoir side connecting pipe (43). Thus, even when apredetermined voltage is applied to the first electrode (44), thereservoir side connecting pipe (43) can prevent a current from flowingfrom the first electrode (44) to the reservoir (30).

The eighth aspect of the present invention is that in any one of theliquid transfer devices of the first to seventh aspects, the one end ofthe first electrode (44) communicates with a lower portion of thereservoir (30), and the other end of the first electrode (44) is open ata level equal to or lower than a bottom of the reservoir (30).

According to the eighth aspect of the present invention, one end of thefirst electrode (44) communicates with a lower portion of the reservoir(30). Thus, the liquid in the reservoir (30) can be transferred into thefirst electrode (44) due to the head of the liquid stored in thereservoir (30). On the other hand, the other end of the first electrode(44) is open at the level equal to or lower than the bottom of thereservoir (30). Thus, when the liquid is transferred from the reservoir(30) into the first electrode (44), the first electrode (44) is filledwith this liquid to its open end. Thus, by creating an electric field ata location close to the open end of the first electrode (44), the liquidat the location close to the open end can be smoothly sprayed andtransferred.

The ninth aspect of the present invention is an air conditionerincluding a heat exchanger (27) for cooling air, a reservoir (30) forstoring a condensed water generated from the air cooled by the heatexchanger (27), and a liquid transfer device (40) for transferring anddischarging the condensed water in the reservoir (30). Any one of theliquid transfer devices of the first to eighth aspects of the presentinvention is used as a liquid transfer device of the air conditioner.

According to the ninth aspect of the present invention, a condensedwater generated from air when the air is cooled by the heat exchanger(27) is stored in the reservoir (30). In other words, the reservoir (30)constitutes a drain pan for collecting the drain water generated at alocation close to the heat exchanger (27). Here, in the presentinvention, the liquid stored in the reservoir (30) is transferred anddischarged to the outside of the system by the liquid transfer device ofthe first to eighth aspects of the present invention.

The tenth aspect of the present invention is that in the air conditionerof the ninth aspect, a copper material is provided in the reservoir (30)so that a copper ion is liberated in the condensed water.

According to the tenth aspect of the present invention, a coppermaterial is provided in the reservoir (30). If the copper material issubmerged in the condensed water, copper ions are liberated from thecopper material into the condensed water. The copper ions suppress theproliferation of bacteria in the condensed water and, consequently,reduce generation of slime due to the proliferation of the bacteria. Asa result, a clogging of the first electrode (44) with a bacteria-inducedsolid matter can be avoided.

The eleventh aspect of the present invention is that in the airconditioner of the tenth aspect, a positive voltage is applied to thefirst electrode (44) from the power source (60), and the secondelectrode (45) is electrically grounded.

According to the eleventh aspect of the present invention, since apositive voltage is applied to the first electrode (44), apositively-charged liquid is sprayed from the first electrode (44).Here, if a positive voltage is applied to the first electrode (44), thecopper ions in the reservoir (30) are not likely to be attracted to thefirst electrode (44), i.e., a positive electrode. As a result, thecopper ions are prevented from being sprayed from the first electrode(44) discharged to the outside of the system together with the liquid.In other words, in the present invention, the copper ions liberated fromthe copper material can be retained in the reservoir (30). Consequently,the bactericidal effect of the copper material can last for a long time.

Effects of the Invention

According to the present invention, a potential difference is appliedbetween the first electrode (44) and the second electrode (45), andthereby, a liquid in the form of small droplets is sprayed from thefirst electrode (44), and the liquid is transferred while suspended inair. If the liquid is transferred in this way, the volume of theoperational sound generated during the transfer of the liquid isdecreased, compared to the case in which a motor is used to transfer theliquid. Thus, according to the liquid transfer device of the presentinvention, a noise generated during the transfer of the liquid can bereliably prevented. In addition, almost no current flows from a powersource (60) when the liquid is transferred by utilizing Coulomb force asin this case. Thus, power consumption required to transfer the liquidcan be significantly reduced as compared to the conventional devices inwhich a motor is used to transfer the liquid, thereby making it possibleto improve energy saving characteristics of the liquid transfer device.

According to the second aspect of the present invention, a positive ornegative voltage is applied to the first electrode (44) from the powersource (60), and the second electrode (45) is electrically grounded.Thus, according to the present invention, a positively-charged liquidcan be sprayed from the first electrode (44) and transferred. On theother hand, the second electrode (45) can be simply grounded, andtherefore, the structure of the liquid spray device can be simplified.

According to the third aspect of the present invention, a flow-in sideguide member (51) guides the liquid sprayed from the first electrode(44), and therefore, the liquid can be reliably transferred in a desireddirection.

Specifically, according to the fourth aspect of the present invention, avoltage having the same electric potential as the voltage applied to thefirst electrode (44) is applied to the flow-in side guide member (51).Thus, according to the present invention, the small droplets of theliquid which flow through the flow path of the flow-in side guide member(51) can be effectively prevented from adhering to the wall surface ofthe flow-in side guide member (51). As a result, the liquid can betransferred in a predetermined direction while keeping the form of smalldroplets and suspended in air.

Further, according to the fifth aspect of the present invention, aflow-out side guide member (53) is grounded. Thus, according to thepresent invention, the small droplets of the liquid can be attracted tothe inner surface of the flow-out side guide member (53) and aggregate.After having aggregated, the liquid can smoothly flow down due to itsown weight, and can be discharged to the outside of the system.

According to the sixth aspect of the present invention, the flow-in pipe(51) and the flow-out pipe (53) are connected to each other by theinsulating discharge side connecting pipe (52). Thus, according to thepresent invention, a current can be reliably prevented from flowing fromthe flow-in pipe (51) to the flow-out pipe (53) even when a positive ornegative voltage is applied to the flow-in pipe (51).

Similarly, according to the seventh aspect of the present invention, thereservoir (30) and the first electrode (44) are connected to each otherby the insulating reservoir side connecting pipe (43). Thus, accordingto the present invention, a current can be reliably prevented fromflowing from the first electrode (44) to the reservoir (30) even when apositive or negative voltage is applied to the first electrode (44).

According to the eighth aspect of the present invention, one end of thefirst electrode (44) is connected to a lower portion of the reservoir(30), and the other end of the first electrode (44) is open at the levelequal to or lower than the bottom of the reservoir (30). This strictureenables the liquid in the reservoir (30) to be transferred to the otherend of the first electrode (44) due to its own weight, and thereby, theliquid in the open end of the first electrode (44) can be. reliablysprayed.

According to the ninth aspect of the present invention, any one of thefirst to eighth liquid transfer devices is used to drain water from anair conditioner. Thus, the volume of the operational sound of the drainpump and the power consumption of the same can be reduced, whichconsequently can achieve low-noise operation and improvement in energysaving characteristics of the air conditioner.

According to the tenth aspect of the present invention, a coppermaterial is provided in the reservoir (30) so that copper ions areliberated in the drain water in the reservoir (30). This structure ofthe present invention can prevent generation of slime and prevent asolid matter from consolidating within the first electrode (44). As aresult, stable operation of the liquid transfer device (40) can beensured for a long time. In addition, since the generation of the slimeis prevented, a foul odor from the reservoir (30) can be prevented, aswell.

Specifically, according to the eleventh aspect of the present invention,a positive voltage is applied to the first electrode (44). Thus,according to the present invention, the copper ions liberated in thereservoir (30) are not likely to flow out of the reservoir (30) to thefirst electrode (44), and a high concentration of copper ions can beretained in the reservoir (30). Thus, the bactericidal effect of thecopper material can last for a long time.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an oblique view showing the outer appearance of an indoor unitof an air conditioner according to an embodiment.

FIG. 2 is a longitudinal cross-sectional view of an indoor unit of anair conditioner according to an embodiment.

FIG. 3 is a plan view of a decorative panel of an indoor unit of an airconditioner according to an embodiment.

FIG. 4 is a schematic diagram of a liquid transfer device according toan embodiment.

FIG. 5 is a schematic diagram depicting an area close to a nozzle of aliquid transfer device according to an embodiment. FIG. 5(A) illustratesa state of liquid before spraying. FIG. 5(B) illustrates a state ofliquid at the beginning of spraying.

Description of Characters

-   -   10 air conditioner    -   27 indoor heat exchanger (heat exchanger)    -   30 drain pan (reservoir)    -   40 drain device (liquid transfer device)    -   43 first insulating pipe (reservoir side connecting pipe)    -   44 nozzle electrode (first electrode)    -   45 ring electrode (second electrode)    -   51 flow-in pipe (flow-in side guide member)    -   52 second insulating pipe (discharge side connecting pipe)    -   53 flow-out pipe (flow-out side guide member)    -   60 power source

Example Embodiments

Embodiments of the present invention are hereinafter described in detailbased on the drawings. An sir conditioner (10) of the present embodimentis for room-air heating and cooling. The air conditioner (10) includesan indoor unit (20) mounted in the ceiling of a room. The indoor unit(20) is connected to an outdoor unit (not shown) via a refrigerant pipe,and a refrigerant circuit for providing a vapor compression typerefrigeration cycle is configured in the air conditioner (10). Arefrigerant circuit of the outdoor unit is provided with elementdevices, such as a compressor, an outdoor heat exchanger, and anexpansion valve.

As shown in FIG. 1, the indoor unit (20) includes a casing body (21) anda decorative panel (22). The casing body (21) is like a flat box whosebottom is open. The decorative panel (22) is attached to the casing body(21) so as to cover the open bottom of the casing body (21). Thedecorative panel (22) has an air inlet (23) in the center. Thedecorative panel (22) has four enlongated air outlets (24) along theperiphery of the air inlet (23).

As shown in FIG. 2, a bell-mouth (25), an indoor fan (26), an indoorheat exchanger (27), and a drain pan (30) are accommodated within thecasing body (21). The bell-mouth (25) is like a cylinder whose bottom isconnected to the air inlet (23). The internal diameter of the bell-mouth(25) becomes wider as it gets closer to the bottom. The indoor fan (26)is located above the bell-mouth (25). The indoor fan (26) constitutes aturbofan. The indoor fan (26) includes a fan motor (26 a) and a blade(26 b) connected to the drive shaft of the fan motor (26 a). When theindoor fan (26) is put into operation, room air is drawn into the casingbody (21) through the air inlet (23) and the bell-mouth (25). The roomair is dispersed radially outward by the blade (26 b) within the casingbody (21). The indoor heat exchanger (27) constitutes a cross fm typeheat exchanger. As shown in FIG. 3, the indoor heat exchanger (27) islocated so as to stand on the upper side of the decorative panel (22)and surround the air inlet (23).

The drain pan (30) is formed on the upper side of the decorative panel(22). The drain pan (30) includes a bottom plate (31), an insidepartition plate (32), an outside partition plate (33), and drain sidepartition plate (34). The bottom plate (31) is formed on the upper sideof the decorative panel (22) and extends across the bottom portion ofthe indoor heat exchanger (27). The inside partition plate (32) isprovided at the inner periphery of the bottom plate (31). The insidepartition plate (32) is positioned radially outward from the air inlet(23) to surround the air inlet (23), and partitions between the indoorheat exchanger (27) and the air inlet (23). The outside partition plate(33) is provided at the outer periphery of the bottom plate (31). Theoutside partition plate (33) is positioned radially outward from theindoor heat exchanger (27) to surround the indoor heat exchanger (27),and partitions between each air outlet (24) and the indoor heatexchanger (27). The drain side partition plate (34) is provided close toa corner of a predetermined portion (lower right portion of FIG. 3) ofthe decorative panel (22). The drain side partition plate (34) extendsalong the indoor heat exchanger (27) such that a drain space (S) iscreated at the outside of the drain side partition plate (34).

The drain pan (30) having the above-described structure constitutes areservoir for storing a condensed water (drain water) generated from theair cooled by the indoor heat exchanger (27). The inside of the drainpan (30), i.e., inside walls of the bottom plate (31) and the partitionplates (32, 33, 34), is coated with a copper material. In other words, acopper member for liberating copper ions in the stored drain water isprovided in the drain pan (30). In addition, the bottom plate (31) ofthe drain pan (30) is inclined so that the stored drain water can flowdown to the drain side partition plate (34).

A drain device (40) is provided in the drain space (S). The drain device(40) constitutes a liquid transfer device for transferring the drainwater stored in the drain pan (30) and discharging the drain water tothe outside the system.

As shown in FIG. 4, the drain device (40) includes a spray part (41) anda transfer part (50). The spray part (41) includes an intake pipe (42),a first insulating pipe (43), a nozzle electrode (44), and a ringelectrode (45). One end of the intake pipe (42) passes through the drainside partition plate (34) and communicates with the inside of the drainpan (30). The one end of the intake pipe (42) is open at approximatelythe same level as the bottom of the drain pan (30). One end of the firstinsulating pipe (43) is connected to the other end of the intake pipe(42). The first insulating pipe (43) is made of an insulating material,such as an insulating resin and an insulator. The first insulating pipe(43) constitutes a reservoir side connecting pipe for connecting betweenthe drain pan (30) and the nozzle electrode (44).

One end of the nozzle electrode (44) is connected to the other end ofthe first insulating pipe (43). The nozzle electrode (44) is curveddownward to form a “U” shape. The other end of the nozzle electrode (44)points upward and is open. The nozzle electrode (44) is made of aconductive material, such as stainless. The other end of the nozzleelectrode (44) is open at the level equal to or lower than the bottom ofthe reservoir (30). The ring electrode (45) is positioned at a placecorresponding to the nozzle electrode (44) such that the ring electrode(45) faces the other end of the nozzle electrode (44). The ringelectrode (45) has an annular shape and is coaxial with the center ofthe other end of the nozzle electrode (44). The ring electrode (45) ismade of a conductive material, such as stainless.

The drain device (40) includes the power source (60) as shown in FIG. 5.The nozzle electrode (44) is connected to a positive electrode of thepower source (60) via electric wiring. In other words, the nozzleelectrode (44) constitutes a first electrode to which a positive voltageis applied. On the other hand, the ring electrode (45) is connected tothe ground of the power source (60) via electric wiring. In other words,the ring electrode (45) constitutes a second electrode which iselectrically grounded. In this way, a potential difference is appliedbetween the nozzle electrode (44) and the ring electrode (45) of thespray part (41) by the power source (60). As a result, a transferoperation in which the drain water in the drain pan (30) is sprayed fromthe nozzle electrode (44) and transferred is carried out at the spraypart (41). Details of the transfer operation are described later.

The transfer part (50) includes a flow-in pipe (51), a second insulatingpipe (52), and a flow-out pipe (53). The flow-in pipe (51) is providedabove the other end (i.e., an open end) of the nozzle electrode (44).The flow-in pipe (51) extends vertically upward from its bottom andcurves obliquely downward at its top portion. The flow-in pipe (51)constitutes a flow-in side guide member which forms a flow path forguiding upward the drain water sprayed from the nozzle electrode (44).Moreover, the flow-in pipe (51) is connected to the above-describedpositive electrode of the power source (60) via electric wiring. Thismeans that a voltage having the same electric potential as the voltageapplied to the nozzle electrode (44) is applied to the flow-in pipe(51).

One end of the second insulating pipe (52) is connected to the topportion of the flow-in pipe (51). The second insulating pipe (52) ismade of an insulating material, such as an insulating resin andinsulator. The second insulating pipe (52) constitutes an insulatingdischarge side connecting pipe for connecting between the flow-in pipe(51) and the flow-out pipe (53). The flow-out pipe (53) is connected tothe other end of the second insulating pipe (52). The flow-out pipe (53)extends obliquely downward and constitutes a flow-out side guide memberfor guiding downward the liquid which flows out of the flow-in pipe(51). Moreover, the flow-out pipe (53) is connected to the ground of thepower source (60) via electric wiring. This means that the flow-out pipe(53) is electrically grounded. The flow-out end of the flow-out pipe(53) communicates with the outside of the casing body (21) and isconnected to a flow path for discharging the drain water (not shown).

-Operation Of Air Conditioner-

Cooling operation of the air conditioner (10) according to the presentembodiment is described. When the compressor of the outdoor unit comesinto operation during the cooling operation, a refrigerant cycle inwhich the outdoor heat exchanger functions as a condenser and in whichthe indoor heat exchanger (27) of the indoor unit (20) functions as anevaporator, is provided.

When the indoor fan (26) is put into operation in this state, room airis drawn into the casing body (21) through the air inlet (23). This airpasses through the bell-mouth (25) and is dispersed radially outward bythe indoor fan (26). As a result, the air goes through the indoor heatexchanger (27). In the indoor heat exchanger (27), a refrigerant whichflows in the indoor heat exchanger (27) absorbs heat from the air andevaporates. As a result, the air is cooled by the refrigerant. The aircooled by the indoor heat exchanger (27) flows along the outer peripheryin the casing body (21), and is supplied to the indoor space through theair outlets (24). The supplied air accomplishes the cooling of theindoor space.

-Transfer Of Drain Water-

When the air is cooled by the indoor heat exchanger (27) in the abovecooling operation, moisture included in the air is condensed and resultsin a drain water near the indoor heat exchanger (27). The drain waterfalls in drops and is collected in the drain pan (30). According to thepresent embodiment, the drain water collected in the drain pan (30) inthis manner is discharged to the outside of the system in the followingmatter.

As the amount of the drain water stored in the drain pan (30) increasesas shown in FIG. 4, the drain water in the drain pan (30) flows out tothe intake pipe (42) due to its own weight (head of water). The drainwater flows through the first insulating pipe (43) to the nozzleelectrode (44), and is led to the tip (open end) of the nozzle electrode(44). As a result, as shown in FIG. 5(A), the drain water at the tip ofthe nozzle electrode (44) is kept at the tip of the nozzle electrode(44) due to surface tension.

In this state, if a potential difference of several thousand volts isapplied between the nozzle electrode (44) and the ring electrode (45)from the power source (60), an electric field is creased at the tip ofthe nozzle electrode (44). If the electric field is created at the tipof the nozzle electrode (44) as described in the above, the drain waterat the tip of the nozzle electrode (44) is polarized, and positiveelectric charges gather at the air-liquid interface of the drain water.As a result, the air-liquid interface at the tip of the nozzle electrode(44) is drawn up to have a conical shape, and part of the liquid ispulled apart from the top of the conical air-liquid interface asdroplets (see FIG. 5(B)). The droplets of the drain water are positivelycharged, and therefore, are attracted to the ring electrode (45) due toCoulomb force. As a result, small droplets of the drain water aresprayed upward from the nozzle electrode (44).

The sprayed drain water moves upward while suspended in air and keepingthe form of small droplets, and flows in the flow-in pipe (51) as shownin FIG. 4. Here, the same electric potential as the electric potentialapplied to the nozzle electrode (44), that is a positive voltage, isapplied to the flow-in pipe (51). This causes the drain water in theflow-in pipe (51) to be repulsive to the inside wall of the flow-in pipe(51) and move further upward while suspended in air. In other words, thedrain water in the flow-in pipe (51) is affected by Coulomb force in adirection separating from the wall surface of the flow-in pipe (51), andthus, the drain water is transferred upward while keeping the form ofsmall droplets without adhering to the wall surface of the flow-in pipe(51). Consequently, the sprayed drain water can be smoothly guidedupward in the flow-in pipe (51).

The drain water which flows out of the flow-in pipe (51) as described inthe above, flows through the second insulating pipe (52) into theflow-out pipe (53). Here, the flow-out pipe (53) is electricallygrounded. Thus, the positively-charged drain water is successivelyattracted to the inside wall of the flow-out pipe (53). As a result, thedrain water in the form of small droplets aggregates on the inside wallof the flow-out pipe (53). After having aggregated, the drain waterflows down smoothly due to its own weight, and is drained to the outsideof the system (such as the outdoors).

Incidentally, in the drain pan (30), so-called slime may be generated inthe drain water because of proliferation of bacteria in the remainingdrain water. If the slime is generated, the nozzle electrode (44) may beclogged with a bacteria-induced solid matter, and continuous transfer ofthe drain water as described in the above may not be possible. Inaddition, the slime may generate a foul odor within the drain pan (30).In view of this, a copper material is provided within the drain pan (30)in the present embodiment.

In this structure, copper ions are liberated from the copper materialinto the drain water in the drain pan (30). The copper ions suppress theproliferation of bacteria in the condensed water and, consequently, alsoreduce generation of slime due to the proliferation of bacteria. As aresult, a solid matter which clogs the nozzle electrode (44) can beavoided. At the same time, a foul odor due to the generation of theslime can be reduced. Further, since a positive voltage is applied tothe nozzle electrode (44), the copper ions liberated in the drain waterare affected by Coulomb force, according to which the copper ions arerepulsive to the positive nozzle electrode (44). Thus, the copper ionsare prevented from flowing out through the nozzle electrode (44)together with the drain water. As a result, the copper ions are retainedin the drain water in the drain pan (30), and thus, the bactericidaleffect of the copper material can last for a long time.

Effect in Embodiments

According to the above embodiment, a potential difference is appliedbetween the first electrode (44) and the second electrode (45) from thepower source (60), and thereby, the drain water in the form of smalldroplets is sprayed from the nozzle electrode (44), and the drain wateris transferred upward while suspended in air. If the liquid istransferred in this way, the volume of the operational sound generatedduring the transfer of the liquid is decreased, compared to conventionalliquid transfer devices in which a motor is used to transfer the liquid.Thus, according to the above embodiment, a noise generated during thetransfer of the liquid can be reliably prevented. In addition, almost nocurrent flows from the power source (60) when the liquid is transferredin this manner. Thus, power consumption required to transfer the liquidcan be significantly reduced as compared to conventional devices inwhich a motor is used to transfer the liquid, thereby making it possibleto improve energy saving characteristics of the liquid transfer device.

Moreover, in the above embodiment, a voltage having the same electricpotential as the voltage applied to the first electrode (44), that is apositive voltage, is applied to the flow-in pipe (51) for guiding thedrain water upward. Thus, according to the above embodiment, smalldroplets of the liquid can be prevented from adhering to the inside wallof the flow-in pipe (51), and these droplets can be transferred upwardwhile reliably suspended in air.

At the same time, in the above embodiment, the flow-out pipe (53) isgrounded so that the drain water in the form of small droplets canadhere to the inside wall surface of the flow-out pipe (53) andaggregate. Thus, the drain water which has aggregated in the flow-outpipe (53) can flow down due to its own weight, and therefore, the drainwater can be smoothly discharged to the outside of the system.

Further, the flow-in pipe (51) and the flow-out pipe (53) are connectedto each other by the second insulating pipe (52), and thus, even when apositive voltage is applied to the flow-in pipe (51), a current does notflow from the flow-in pipe (51) to the flow-out pipe (53). Similarly,the drain pan (30) and the nozzle electrode (44) are connected to eachother by the first insulating pipe (43), and thus, even when a positivevoltage is applied to the nozzle electrode (44), a current does not flowfrom the nozzle electrode (44) to the drain pan (30).

Moreover, in the above embodiment, a copper material is provided in thedrain pan (30) so that copper ions are liberated in the drain water inthe drain pan (30). Generation of slime can thus be prevented by thecopper ions, and a solid matter which clogs the nozzle electrode (44)can be avoided. As a result, stable operation of the drain device (40)can be ensured for a long time. In addition, since the generation of theslime is prevented, a foul odor from the drain pan (30) can beprevented, as well. Further, the copper ions liberated in the drain pan(30) are repulsive to the positive nozzle electrode (44), and therefore,the copper ions can be prevented from flowing out through the nozzleelectrode (44). As a result, a high concentration of the copper ions canbe retained in the drain pan (30), and the bactericidal effect of thecopper material can last for a long time.

<<Other Embodiments>>

The following structures may be applied in the embodiment described inthe above.

According to the above embodiment, a positive voltage is applied to thenozzle electrode (44) while the ring electrode (45) is grounded.However, a negative voltage may be applied to the nozzle electrode (44)while the ring electrode (45) is grounded. In this case, anegatively-charged drain water is sprayed from the nozzle electrode(44). In this case, the drain water can be prevented from adhering tothe inside wall of the flow-in pipe (51) by applying a negative voltageto the flow-in pipe (51), as well as to the nozzle electrode (44).Applying a potential difference between the nozzle electrode (44) andthe ring electrode (45) by applying a positive voltage to the nozzleelectrode (44) and a negative voltage to the ring electrode (45) may bepossible, or any other structure that can apply a potential differencebetween the electrodes (44, 45) may be possible.

According to the above embodiment, one nozzle electrode (44)communicates with the drain pan (30) to spray and transfer the drainwater from the nozzle electrode (44). However, a plurality of nozzleelectrodes (44) may communicate with the drain pan (30) to spray thedrain water from the respective nozzle electrodes (44) simultaneously.In this case, the transfer parts (50) may be provided so that each ofthe transfer part (50) may correspond to its associated nozzle electrode(44), or a flow path for guiding the sprayed drain water may be providedsuch that the flow path is branched and connected to the nozzleelectrodes (44).

Further, in the above embodiment, a filter for capturing a solid mattermay be provided at a location in the flow path of a drawn water from theintake end of the intake pipe (42) to the intake end of the nozzleelectrode (44). A clogging of the nozzle electrode (44) can beeffectively avoided by capturing a solid matter by the filter.

In the above embodiment, the drain device (40) is used as a drain devicefor the air conditioner (10). However, as a matter of course, the draindevice (40) can be used for purposes other than the above, as long asthe drain device (40) is used to transfer a liquid.

The embodiments described in the above are essentially preferableexamples which are not intended to limit the present invention, itsapplication, or its range of use.

Industrial Applicability

As described in the above, the present invention is useful as a liquidtransfer device for transferring a liquid in the reservoir, and as anair conditioner including the liquid transfer device.

1. A liquid transfer device for transferring a liquid in a reservoir(30), comprising: a tubular first electrode (44) whose one endcommunicates with the reservoir (30) and whose other end is open; asecond electrode (45) provided at a location corresponding to the otherend of the first electrode (44); and a power source (60) for applying anpotential difference between the first electrode (44) and the secondelectrode (45), thereby creating an electric field at a location closeto the other end of the first electrode (44), wherein the liquid in thereservoir (30) is sprayed from the other end of the first electrode (44)due to the electric field, and thereby the liquid is transferred.
 2. Theliquid transfer device of claim 1, wherein a positive voltage or anegative voltage is applied to the first electrode (44) from the powersource (60), and the second electrode (45) is electrically grounded. 3.The liquid transfer device of claim 2, comprising a flow-in side guidemember (51) which forms a flow path for guiding the liquid sprayed fromthe first electrode (44).
 4. The liquid transfer device of claim 3,wherein a voltage having a same electric potential as the voltageapplied to the first electrode (44) is applied to the flow-in side guidemember (51).
 5. The liquid transfer device of claim 3 or claim 4,comprising a flow-out side guide member (53) which forms a flow path forguiding the liquid that flows out of the flow-in side guide member (51)and which is electrically grounded.
 6. The liquid transfer device ofclaim 2, comprising: a flow-in pipe (51) through which the liquidsprayed from the first electrode (44) flows and to which a voltagehaving a same electric potential as the voltage applied to the firstelectrode (44) is applied; a flow-out pipe (53) through which the liquidthat flow out of the flow-in pipe (51) flows and which is electricallygrounded; and an insulating discharge side connecting pipe (52) forconnecting between the flow-in pipe (51) and the flow-out pipe (53). 7.The liquid transfer device of claim 1, comprising an insulatingreservoir side connecting pipe (43) for connecting between the reservoir(30) and the first electrode (44).
 8. The liquid transfer device ofclaim 1, wherein the one end of the first electrode (44) communicateswith a lower portion of the reservoir (30), and the other end of thefirst electrode (44) is open at a level equal to or lower than a bottomof the reservoir (30).
 9. An air conditioner comprising: a heatexchanger (27) for cooling air; a reservoir (30) for storing a condensedwater generated from the air cooled by the heat exchanger (27); and aliquid transfer device (40) for transferring and discharging thecondensed water in the reservoir (30), wherein the liquid transferdevice (40) is the liquid transfer devices of claim
 1. 10. The airconditioner of claim 9, wherein a copper material is provided in thereservoir (30) so that a copper ion is liberated in the condensed water.11. The air conditioner of claim 10, wherein a positive voltage isapplied to the first electrode (44) from the power source (60), and thesecond electrode (45) is electrically grounded.